Feed-valve for air-brake systems.



' Patented Feb.3,19 14.-

J, R. SNYDER. FEED VALVE FOR AIR BRAKE SYSTEMS.

APPLIGATION FILED JUNE 24, 1912.

INVE TOR fi wgflw %a UNITED STATES PATENT @FFTQE.

JACOB RUSH SNYDER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO PERCY E. BONNER, OF PITTSBURGH, PENNSYLVANIA.

FEED VALVE FOB. AIR-BRAKE SYSTEMS.

To all whom it may concern:

Be it known that I, JAooB RUSH SNYDER, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Feed Valves for Air Brake Systems, of which the following is a specification.

This invention relates to what are known as feed valves for air brake systems, that is, valves for supplying the train or brake pipe with a definite pressure from the main reservoir or other source which may fluctuate more or less, and which generally is much higher than the pressure desired to be carried in the train pipe.

The object of the invention is to provide a feed valve for air brake systems which is.

of simple construction, not liable to derangement, and whereby the pressure to be carried by the train pipe can be readily controlled by the engineer.

The invention comprises a valve constructed and arranged as hereinafter described and claimed.

In the accompanying drawings Figure 1 is-a longitudinal section through one form of valve embodying the invention; Fig. 2 is a transverse section on the line 22, Fig, 1; and Fig. 3 is a longitudinal section through another form of valve embodying the invention.

The valve comprises a suitable casing shown in the drawings as formed of two parts marked 1 and 2 respectively and suitably joined together, such as by the compression bolts 3 shown in Fig. 1, or the threaded connection 4, shown in Fig. 3. Between the two casing members is a suitable movable abutment, which may be a piston but which is shown as a diaphragm 5, for actuating the control valve, said diaphragm dividing the easing into two chambers, to wit, a chamber 6 in the casingmember 1 and a chamber 7 in the casing member 2. The chamber 6 has a connection 8 to the train pipe, and a valve controlled connection 9 with the main reservoir pipe 10. Between the main reservoir connection 10 and train pipe connection 8 is a partition 11 provided with a feed opening 12 controlled by valve 13, the latter being shown as a slide valve cooperating with seat 14 formed on a bushing 15 driven into a bore 16 in the casing member 1 and one wall of which forms the partition 11. The inner end of Specification of Letters Patent.

Application filed June 24, 1912.

Patented Feb. 3, 191a.

SeriaLNo. 705,565.

this bore is closed by the integral wall 17 while its outer end is closed by a plug 18. The slide valve 13 is held to its seat by spring 19, and said valve is engaged by a projection 20 extending through the feed opening 12 and forming a part of a stem 21 at one end secured to and actuated by the diaphragm 5, and at its other end guided in an opening'23 in a plug 24: threaded into the-end wall of easing member 1. The slide valve 13 controls the opening 12 which forms the communication between the main reservoir connection 9 and train pipe connection 8.

Thediaphragm 5 is subject at all times to train pipe pressure in chamber 6. Its opposite face is subject to a predetermined fixed pressure in the closed chamber 7. This pressure, preferably, is derived from the main reservoir through pipe 25 controlled by the three-Way cut-off cook 26 and having connected thereto a suitable 27. By means of the cook 26 any amount of pressure can be admitted to chamber 7 or released therefrom. The engineer will admit pressure to the chamber 7 until the gage 27 stands at the amount of pressure to be carried in the brake pipe. YVhenever the brake pipe pressure falls below this amount, the diaphragm 5 moves to the left, carrying with it the slide valve 13 to open communication from the main reservoir to the train pipe, and as soon as the pressure in the train pipe and in chamber 6 balances the pressure in chamber 7 or very slightly exceeds the same, the diaphragm is moved to the right to cut off further communication betweenthe main reservoir and the train pipe. The slide valve 13 will move upon a very slight unbalancing of pressures on the two faces of diaphragm 5, not to exceed one-half pound. Consequently, the pressure in the brake pipe is automatically kept at substantially the pressure indicated by the gage 27.

If desired, the air pressure in chamber 7 may begsupplemented by a spring 30, as shown in Fig. 3, bearing against diaphragm 5 and arranged to be adjusted by screw 31. The strength of spring 30, preferably, will be equal to the minimum pressure to be carried in the train pipe, so that it will take care of the minimum pressure therein without additional fluid pressure in chamber 7 Any desiredpressure, however, can

pressure gage re; Lose /e3 be carried in the train. pipe by merely admitting to chamber '7 an amount of pressure equal to the ditl'erence between the pressure to be carried by the train pipe and the strength or" spring 80.

Suitable stops 32 and 33 in the casing are provided for limiting the movement of the diaphragm 5.

The feed valve described is very sensitive, the valve itself being a slide valve and, therefore, not atlected by dii'l erences of pressure on opposite sides thereof. The engineer can absolutely control the pressure in the train pipe by merely admitting to cham ber 7 fluid pressure until the gage 2? stands at the pressure to be carried in the train pipe. lie can r gulate the pressure in chamber 7 by the coc I 26 and alter it from time to time as desired, by either admitting more fluid pressure thereto or releasing it therefrom. T he friction of the valve on its seat so slight that the diaphragm 5 moves the valve upon only slight unbalancing of pressures on the opposite faces of said dia phragm so that practically uniformity of pressure in the train pipe is assured W hat claim is 1. A feed valve for air brakes comprising a casing having connections to the main reservoir and the train pipe, a valve seat in said casing having a. port ailording communication between the main reservoir and the train pipe connections, a slide valve cooperating with said seat and controlling said port, and a movable abutment controlling said valve and subject on one side to train pipe pressure and on its opposite side to a predetermined fined pressure oi a trapped body of air entirely independent of pressure variations in brake applications.

2. feed valve for air brakes comprising a casing having connections to the main reservoir and the train pipe, a seat in said casing having port al'lording communication 0 between the train pipe and the main reservoir connections, a slide valve cooperating vvith said seat and controlling said port, a movable abutment controlling said valve and subject on one side to train pipe pressure and on its opposite side to pressure in a closed chamber arranged to be entirely independent of pressure variations in brake applications, and means arranged to admit pressure to and exhaust pressure from said chamber.

3. A feed valve for air brakes comprising a casing having connections to the main resorvoir and the train pipe, a valve controlling communication between said connections, a movable abutment controlling said valve and subject on one side to train pipe pressure and on its opposite side to pressure in a closed chamber and arranged to be entirely independent oi. variations in pressure in brake applications, and means independent of the engineers brake valve for admitting a predetermined pressure to said chamber.

4. A feed valve for air brakes comprising a casing having connections to the main reservoir and the train pipe, a valve cont-rolling conununication between said connections, a movable abutment controlling said valve and subject on one side to train pipe pressure and on its opposite side to pressure in a closed chamber arranged to be entirely inde pendent of variations in pressure in brake applications, and manually operated connections from the main reservoir to said closed chamber for admitting a predetermined pressure into said chamber.

5. A teed valve for air brakes comprising a casing having connections to a source of pressure and the train pige, a valve control communication between said connections, a m vable abutment controlling said valve and subject on one side to train pipe pressure and on its opposite side to pressure in closed chamber arranged to be entirely independent of pressure variations in brake applications, and a manually operated valve independent of the engineers brake valve and arranged to admit pressure to and eX- haust oressure from said chamber.

6. A teen valve for air brakes comprising a casing; having connections to a source of pressure and the train pipe, a valve controlling communication between said connections, a movable abuti'nent controlling said valve and subject on one side to train pipe pressure and on its opposite side to pressure in a closed chamber arranged to be entirely indepe dent of pressure variations in brake applications, means independent of the enginr-icr s brake valve for admitting pressure to said chamber, and means for indicating the degree of pressure in said chamber.

In testimony whereof I have hereunto set my hand.

JACOB RUSH SNYDER.

lVitnesses F. lV. illiLLnn, l VILLIAM lVI-IARTON.

Copies oi this patent may be obtained for five cents each, by addressing the Commissioner of Yatente, Washington, 31). C. 

